feat(wasm-api): add debug() core API function

thi-ng · Aug 22, 2022 · ca01978 · ca01978
1 parent 0e27cc7
commit ca01978
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Showing 4 changed files with 17 additions and 0 deletions.
diff --git a/packages/wasm-api/include/wasmapi.h b/packages/wasm-api/include/wasmapi.h
@@ -7,9 +7,13 @@ extern "C" {
 #include <stddef.h>
 #include <stdint.h>
 
+// Declares an imported symbol from named import module
+// The prefix is only used for the C side, NOT for exported name
 #define WASM_IMPORT(MODULE, TYPE, NAME, PREFIX)                     \
   extern __attribute__((import_module(MODULE), import_name(#NAME))) \
   TYPE PREFIX##NAME
+
+// Same as EMSCRIPTEN_KEEP_ALIVE, ensures symbol will be exported
 #define WASM_KEEP __attribute__((used))
 
 // Generate stubs only if explicitly disabled by defining this symbol
@@ -53,6 +57,8 @@ WASM_IMPORT("wasmapi", void, _printF64Array, wasm)(void* addr, size_t len);
 WASM_IMPORT("wasmapi", void, _printStr0, wasm)(void* addr);
 WASM_IMPORT("wasmapi", void, _printStr, wasm)(void* addr, size_t len);
 
+WASM_IMPORT("wasmapi", void, debug, wasm_)(void);
+
 void wasm_printPtr(void* ptr) { wasm_printU32Hex((size_t)ptr); }
 
 #ifdef __cplusplus

diff --git a/packages/wasm-api/include/wasmapi.zig b/packages/wasm-api/include/wasmapi.zig
@@ -165,10 +165,16 @@ pub fn printStr(msg: []const u8) void {
     _printStr(@ptrToInt(msg.ptr), msg.len);
 }
 
+/// Calls std.fmt.allocPrint to format given string, then calls `printStr()`
+/// to output it via JS, then frees string's memory again
+/// (Only available if the allocator used by `_wasm_allocate()` hasn't been disabled.)
 pub fn printFmt(comptime fmt: []const u8, args: anytype) void {
     if (allocator) |alloc| {
         const res = std.fmt.allocPrint(alloc, fmt, args) catch return;
         defer alloc.free(res);
         printStr(res);
     }
 }
+
+/// Triggers the JS/browser debugger
+pub extern "wasmapi" fn debug() void;
diff --git a/packages/wasm-api/src/api.ts b/packages/wasm-api/src/api.ts
@@ -148,6 +148,7 @@ export interface CoreAPI extends WebAssembly.ModuleImports {
 	_printF64Array: (addr: number, len: number) => void;
 	_printStr0: (addr: number) => void;
 	_printStr: (addr: number, len: number) => void;
+	debug: () => void;
 }
 
 export interface WasmTypeBase {

diff --git a/packages/wasm-api/src/bridge.ts b/packages/wasm-api/src/bridge.ts
@@ -95,6 +95,10 @@ export class WasmBridge<T extends WasmExports = WasmExports>
 
 			_printStr: (addr: number, len: number) =>
 				this.logger.debug(this.getString(addr, len)),
+
+			debug: () => {
+				debugger;
+			},
 		};
 	}